Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 842 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.🔍 Which sensor would you use to keep an incubator warm? (a) a temperature sensor (b) a light sensor (c) a gas sensor (d) a sound sensor
2. 2.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) LED (b) capacitor (c) voltmeter (d) diode
3. 3.True or false: a push button springs back when let go. (a) True (b) False
4. 4.🔋 Does an air conditioner give electricity or use electricity? (a) gives electricity (b) uses electricity
5. 5.True or false: to throw cells in a fire is not safe. (a) True (b) False
6. 6.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) so all go off together (c) to make bulbs dim (d) to save copper only
7. 7.🔍 Which sensor would you use to close a window in rain? (a) a sound sensor (b) a light sensor (c) a rain sensor (d) a gas sensor
8. 8.🔍 Which is the odd one out? (a) a motion sensor (b) a push button (c) a temperature sensor (d) an LED
9. 9.🔘 Which kind of switch flips up or down? (a) a tilt switch (b) a toggle switch (c) a push button (d) a reed switch
10. 10.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
11. 11.🔺 A current of 0.25 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
12. 12.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
13. 13.Which of these saves electricity? (a) use daylight to read (b) leave the TV on standby (c) use old filament bulbs (d) iron one shirt at a time
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = R ÷ V (d) I = V ÷ R
15. 15.🔍 Which is the odd one out? (a) build with an adult near (b) use mains for a project (c) dry your hands first (d) use small battery cells
16. 16.🌈 A resistor has the colour bands yellow, violet, orange. What is its value in kilo-ohms (kΩ)? =
17. 17.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) any band (c) the widest gap (d) the gold band
18. 18.🔘 A bulb and a cell are joined through 5 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
19. 19.Which job is done by the reset button? (a) brings power and code (b) keeps the voltage steady (c) runs the program (d) restarts the program
20. 20.Which of these is a good habit? (a) post your live location (b) read app permissions (c) ignore update messages (d) share the Wi-Fi key
21. 21.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
22. 22.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the pins (b) the reset button (c) the main chip (d) the voltage regulator
23. 23.🌐 In an IoT system, which part shows data to you? (a) phone app (b) cloud server (c) sensor (d) Wi-Fi
24. 24.🔍 Which is the odd one out? (a) an iron nail (b) a rubber band (c) a woollen thread (d) a ceramic cup
25. 25.Which job needs a pump? (a) move water to plants (b) turn to an exact angle (c) show the temperature (d) open a gate to 90°
26. 26.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
27. 27.🔁 What does a variable do in a program? (a) stores a value (b) blinks an LED (c) joins two wires (d) measures light
28. 28.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the colour of light (d) the length of a wire
29. 29.Which of these is an input? (a) a motor (b) an LED (c) a servo motor (d) a push button
30. 30.True or false: an LED lamp mainly gives out light. (a) True (b) False
31. 31.🔁 repeat 6 times { repeat 4 times { beep } }
    How many beeps are there?
32. 32.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets smaller (c) gets bigger (d) stays the same
33. 33.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
34. 34.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
35. 35.📏 Which unit measures resistance? (a) watt (W) (b) ampere (A) (c) ohm (Ω) (d) volt (V)
36. 36.🔐 Is it a good or a risky habit to share only needed data? (a) good habit (b) risky habit
37. 37.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 2 cm. What happens? (a) buzzer beeps (b) buzzer is silent
38. 38.🔍 Which is the odd one out? (a) a steel spoon (b) a wooden stick (c) a glass marble (d) a paper strip
39. 39.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
40. 40.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = I ÷ V (c) R = V × I (d) R = V + I

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